Why Does My Neck Hurt From Side Sleeping?

Why does my neck hurt from side sleeping? If you regularly wake up with neck pain or stiffness after sleeping on your side, you may wonder why a sleeping position that feels comfortable can leave your neck feeling sore in the morning.

Side sleeping itself is not necessarily bad for your neck. The problem is often how your head and neck are positioned while you sleep. Since you can remain in the same position for several hours, even a small amount of bending or twisting may contribute to neck discomfort by the time you wake up.

Understanding what happens to your neck during side sleeping can help explain why this problem occurs.

Why Does Your Neck Hurt When Sleeping on Your Side?

The main reason your neck may hurt from side sleeping is that your neck is either bending upward or downward toward the mattress instead of staying in its neutral position. The most common reason is that most people don’t have the right pillow to support their head and neck properly when side sleeping.

When you’re sleeping on your side, the gap between your head and the mattress is so big that hardly any regular pillows are able to fill it. What you need is an actual neck support pillow that is designed to specifically support you as a side sleeper. You can explore more about our side sleeping pillow collections to give you an idea of how side sleeping pillows are designed.

Unsupportive Pillow Material

This is another big factor that can cause neck pain when side sleeping. Most pillows are designed for comfort instead of real support. That’s why the majority of pillows are made of feathers. Feather pillows will give you that softness and comfort when first lying down, but they are by no means able to provide consistent support for your head and neck night after night.

An average person’s head can weigh somewhere between 10 and 12 pounds. With this kind of weight, a feather pillow will flatten out as soon as you put pressure on it. And the bad thing is it won’t be able to return to its original shape. This can strain your neck for hours while you sleep, which leads to neck pain and stiffness when you wake up.

Your Pillow Can Change the Position of Your Neck

Your pillow plays an important role in determining where your head rests while you sleep. A pillow that is too thin may allow your head to sink toward the mattress. A pillow that is too thick may push your head upward. Both situations are not good for your neck.

In addition, a pillow that’s comfortable for back sleeping may not be as comfortable for side sleeping. The reason being is that for back sleepers, they need a pillow with a lower loft so their body can stay in natural alignment when they sleep. However, for side sleepers, they will need a pillow with a higher loft to be able to fill the gap between the head and the mattress that is created by their shoulders. You can take some time to learn more about what pillow chiropractors recommend for side sleepers to give you an idea of what requirements a pillow that’s designed for side sleepers must have.

Your Shoulder Width Matters

This is why the saying "one size doesn’t fit all" also applies to side sleeping pillows. Since everyone’s shoulder width is different, they need different-sized pillows. You can measure from the bottom of your neck out to the edge of your shoulder to decide the thickness of your side sleeping pillow. These numbers should match or be somewhat close to each other in order to maintain the natural alignment of your body when you sleep.

Sleeping in One Position for Hours Can Contribute to Stiffness

It doesn’t matter how perfect your sleeping posture is, our body isn’t designed to stay in one position for too long. Doing so can cause you to feel pain, aches, and stiffness by the time you wake up. So try not to sleep in one position for hours. Switching between back and side sleeping positions can help prevent putting too much pressure on a certain part of your body, enabling you to sleep better and wake up without neck pain and stiffness.

Your Neck May Be Twisted While You Sleep

Side sleeping can also cause neck discomfort when your head is turned rather than facing forward. For example, some people naturally rotate their head toward the mattress or toward the ceiling while sleeping on their side. This can create additional rotation in the neck.

The combination of side bending and rotation may make the neck feel particularly stiff in the morning. Your overall sleeping posture can therefore matter just as much as the fact that you are sleeping on your side.

Final Thoughts

So, why does your neck hurt from side sleeping?

The most common explanation is that your head and neck are being held in an uncomfortable position for an extended period. Your pillow, shoulder width, sleeping posture, and the amount of time you spend in one position can all influence how your neck is positioned during the night.

If you frequently wake up with neck pain after sleeping on your side, understanding these factors is the first step toward identifying what may be contributing to the problem.

For practical tips on improving your sleeping position and choosing the right support, see our guide on how to avoid neck pain when side sleeping.